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DIY'r
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523 Posts
Discussion Starter · #1 ·
Hi All,

The 2008 NEC is adopted in my area, and I've been studying the Code.

210.4(C) says that MWBCs can only supply line-to-neutral loads, but Exception 2 says that L-to-N loads are not required if both ungrounded conductors are on a common trip breaker.

210.4(B) says that all MWBCs must have both ungnd. conductors on a common-trip, so it seems that all MWBCs under code would meet the exception above.

So am I right in surmising that I could have a 3 gang box fed by a single MWBC with 3 receptacles, each wired like this:

L1-N (120V)
L2-N (120V)
L1-L2 (240V) or L1-L2-N for a 4-wire 120V/240V receptacle.

I'm asking because I'm planning on redoing the electrical in my garage, and I figure that would give me the most flexibility on how I use some of my circuits in the future. I just think I might be missing something that prohibits it..
 

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Licensed Electrical Cont.
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7,829 Posts
Yes, under the 2008 NEC all MWBC's require a common-trip breaker.

Yes, what you propose is fine.

I have to ask, are you absolutely sure your area is under the 2008 NEC for residential? I know your area well but have not lived there for quite a while. I was under the impression that ALL one and two family residential dwellings in NYS followed the 2007 NY Residential Code.
There are some very distinct difference between the two.
 

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DIY'r
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523 Posts
Discussion Starter · #3 ·
Thanks for the quick response, Speedy.

I'm 95% sure that the 2008 NEC is in force. The Town of Oyster Bay code is online, and in regards to electrical standards it says:

A.All new electrical wiring or installations or extensions of or alterations or removal of existing installations shall be made in conformity with the requirements of the National Electrical Code, being particularly the latest edition of the National Fire Electrical Code in effect at the time thereof, as recommended by the National Fire Protection Association, except where the provisions of this chapter or any other provisions of this Code or other ordinances of the town shall differently prescribe, in which event compliance with the provisions of such provisions of this Code or town ordinance shall be recognized as proper compliance with this chapter.

The town code has very few specifics itself about electrical installations; it prohibits Al wiring 4 AWG and smaller, prohibits NM cable in commercial, etc.

This is the page I was looking at, in case you were curious..

http://gcp.esub.net/cgi-bin/om_isap...nfobase=oyster.nfo&softpage=Browse_Frame_Pg42

You're making me doubt it now though..
 

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Licensed Electrical Cont.
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7,829 Posts

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DIY'r
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523 Posts
Discussion Starter · #6 · (Edited)
Now how can you have "hicksville" north of of Mason Dixon line?:brows:
I knew I shouldn't have put that in my profile! :eek:

It's the stupidest name for a town (except maybe Intercourse, PA), but I grew up in the area so I just got used it...

BTW - In my defense it's not that hickish.. I've got 9 Home Depots within 10 miles of my house. (Literally 9). :)
 
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